Numerous applications require high purity or ultra-high purity ammonia (e.g., having low water content). Typically, higher purities of ammonia are achieved through a distillation process. However, conventional distillation processes may not yield ammonia of sufficient purity. Often the actual purity levels achieved are well below a predicted purity. Thus, additional distillation cycles may be needed to further increase the purity of the distilled ammonia.
However, in conventional ammonia distillation processes, intrinsic system contaminants and/or environmental contaminants may be introduced to the distilled ammonia from the distillation system. For example, contamination (e.g., moisture, chlorides and the like) from the internal surfaces of the distillation system or from the exterior environment may be introduced to the ammonia in its vapor form and/or its liquid form as the ammonia passes through the distillation system. Maintaining an internally clean system and preventing exterior contamination from entering the system may be a difficult process. Additionally, environmental contamination may be introduced to the distilled ammonia during transfer of the distilled ammonia between distillation cycles.
Further, contaminated ammonia may be corrosive to metal material (e.g., aluminum, copper and the like). Such corrosive attacks may damage ammonia distillation systems or other end use systems utilizing high purity ammonia.
Accordingly, those skilled in the art continue with research and development efforts in the field of ammonia distillation for use in high purity applications.